1. Field of the Invention
The present invention relates to an image processing apparatus which carries out photogrammetry based on a plurality of continuous images obtained from a moving image, and in particular, relates to an image processing apparatus that can easily and effectively manage various data required for orientation processing.
2. Description of the Related Art
The theory of photogrammetry has been researched for a long time, and in particular, the theory has been widely used in the field of the civil engineering. This photogrammetry is a technique for determining three-dimensional information of a photographed object from stereo-pair images photographed from two directions. A summary of photogrammetry will be explained hereinafter.
First, the photographed object is photographed from two directions by a camera. As a result, stereo-pair images consisting of right and left images are obtained. The worker determines 6 points (control points) corresponding between right and left images, and obtains these coordinate values on each image. Then, relative orientation is carried out by using the coordinates values of these 6 points. The relative orientation is a method for calculating relative coordinates and three-axial rotary angles of a camera photographing right and left images. The scales and tilts of right and left images are unified by the relative orientation, and stereo model (stereo images) in which vertical parallax is removed can be made (refer to FIG. 2). These stereo images are equivalent to right and left images obtained by a stereovision imaging system in which optical axes of two cameras are parallel to each other.
Furthermore, when the number of common points corresponding between multiple stereo-pair images is 3 points or more, connective orientation is possible. This connective orientation is a method for converting into the same coordinate system by unifying tilts and scales between stereo models. The connective orientation is carried out by fixing orientation elements of one image and manipulating orientation elements of the other image. Then, the three-dimensional coordinates of each point can be measured by the principle of triangulation (stereo method) from each model obtained by the connective orientation. Details of this stereo method, the relative orientation, and the connective orientation are described later. Furthermore, inner orientation is required according to the lens of the camera. The inner orientation is a method for calculating a focal length of lens and correction factors for correcting lens distortion.
In recent years, a technique for automating setting work of control points in photogrammetry by an image processing has been proposed (for example, see Japanese Unexamined Patent Application Publication No. 2005-332177). According to a technique described in JPA 2005-332177, first, an object is photographed as a moving image, while its photographed position progressively changes. Then, characteristic points are extracted in the first frame of the moving image data, and the characteristic points are set as control points. The control points are tracked in each frame of the moving image data, and control points in each frame are set. Then, two frames having control points are selected as stereo-pair images, and the above-mentioned photogrammetry analysis is carried out.
On the other hand, an invention described in Japanese Unexamined Patent Application Publication No. 10-191279 is a technique of an embedding system for embedding any data into a moving image. This system comprises a transmitter-side computer which overwrites any embedded data on a partial image at a different position between a plurality of continuous images and which transmits the plurality of continuous images, and further comprises a receiver-side computer which receives the plurality of continuous images and which overwrites a partial image at the same position in previous image on a position embedded an embedded data in each image. As a result, the moving image, and information related to the moving image, can be transmitted and received by a plurality of computers without lowering transmission performance.